Senior Mainframe Administrator (z/OS and Networking)

DivIHN (pronounced divine ) is a CMMI ML3-certified Technology and Talent solutions firm. Driven by a unique Purpose, Culture, and Value Delivery Model, we enable meaningful connections between talented professionals and forward-thinking organizations. Since our formation in 2002, organizations across commercial and public sectors have been trusting us to help build their teams with exceptional temporary and permanent talent.

Visit us at to learn more and view our open positions.

• We are seeking a Senior Mainframe Administrator with extensive experience in IBM z/OS systems and mainframe networking to lead operational support, system maintenance, and performance optimization efforts.
• This role will involve advanced troubleshooting, system configuration, and collaboration with technical teams to ensure the stability, availability, and security of mission-critical mainframe environments.

• Provide advanced system administration and technical leadership for IBM z/OS mainframe systems.
• Oversee system performance management, tuning, and capacity planning to ensure optimal operations.
• Manage and maintain network configurations, connectivity, and communication protocols (SNA, TCP/IP, VTAM, NJE, etc.) in the mainframe environment.
• Troubleshoot and resolve complex system, network, and application-level issues, driving root cause analysis and long-term corrective actions.
• Lead and perform IPL (Initial Program Load) activities, system backups, recovery, and disaster recovery testing.
• Plan and apply system maintenance, software upgrades, and PTFs, coordinating with system programmers and vendor support.
• Administer and enforce mainframe security policies (RACF, ACF2, or Top Secret), including user access management and compliance controls.
• Participate in and provide guidance for problem, change, and incident management processes, ensuring timely resolution and documentation.
• Collaborate with infrastructure, application, and network teams to ensure seamless integration and high availability across systems.
• Mentor junior administrators and contribute to process improvement and automation initiatives.

• 7+ years of hands-on experience in mainframe system administration with deep expertise in z/OS.
• Strong understanding of mainframe networking, including SNA, TCP/IP, VTAM, NJE, and related tools (NetView, Wireshark, etc.).
• Proficiency with JCL, TSO/ISPF, and monitoring tools such as SDSF, RMF, OMEGAMON, SysView, or equivalent.
• Experience with JES2/JES3 job management, system logs, and IPL processes.
• Solid knowledge of storage management, dataset allocation, and HSM principles.
• Expertise in security administration using RACF, ACF2, or Top Secret.
• Familiarity with automation tools, scheduling systems (CA-7, Control-M), and performance tuning techniques.
• Strong troubleshooting, diagnostic, and analytical abilities.
• Experience working in high-availability, enterprise-scale environments.

DivIHN is an equal opportunity employer. DivIHN does not and shall not discriminate against any employee or qualified applicant on the basis of race, color, religion (creed), gender, gender expression, age, national origin (ancestry), disability, marital status, sexual orientation, or military status.